Problem: Evaluate the following expression when $c = 1$ and $d = 10$. $8$ $c$ $ + 7$ $d$ $ - 5$
Solution: Substitute $1$ for ${c}$ and $10$ for ${d}$ $ = 8{(1)} + 7{(10)} - 5 $ $ = 8 + 70 - 5 $ $ = 73$